Conventional methods and/or circuits for wake-up schemes are based on a fixed delay element. The fixed delay element is implemented either on-chip or off-chip. One such conventional method implements an R-C charging circuit configured to cause the wake-up event (e.g., generation of an interrupt). Another such conventional method implements a free-running low power oscillator.
Conventional off-chip timers (i) require additional pins on the microcontroller device and (ii) require external components (e.g., R-C charging circuit). Conventional on-chip timers (i) are not accurate, (ii) lack a mechanism to improve accuracy, (iii) require several cycles of wake-up and re-suspend for long delays and (iv) have high power consumption. Additionally, both off-chip and on-chip timers have limited wake-up time ranges.